It comes on when the temp is 120F which has only happened once when i manually tested fail over it in the fall works well pilot lights and it takes over heating.I've been burning since the summer so this thing is just basically off as the S260 does not let the temp get below 140-150F.

It has a vent electronic damper that is supposed to open and close when the unit is on but it's not fully closed in the off and i'm loosing btu's up the stack.I have not completely turned it off for fear that i would also be shutting off all the relays hooked up to it.

So my questions are:

1. Is there an easy way to troubleshoot the open/closing of the damper?2. Does anyone know the replacement damper for this slant/fin sp-52 60 damper? 3. Is it possible to isolate power to the relays from power to the unit/ignition?

3. Realized the top of the hood was rubbing against the edges of the vent damper and preventing it from operating normally thus preventing the ignition from working. It doesnt work unless the vent damper is in the open 90 position. Tested this by tweeking temp on the hi/low of aquastat. The motor seems to work fine but any small tension and it will stop. Opens and closes slowly. Not sure if it needs some oiling or it's on its last leg?IMAG0101 by ValterBorges, on Flickr

4. Since the goal is to stop the thermal syphoning and prevent the drafting of all the heat from the propane boiler out thru the side-shot. I disconnected the the 24v connection between the damper connections and ignition connection. Then I again tweeked the aquastat and no movement on the vent and no firing on the ignition.IMAG0107 by ValterBorges, on FlickrIMAG0105 by ValterBorges, on Flickr